Radiation detector, radiographic imaging device, and radiation detector manufacturing method

ABSTRACT

A radiation detector includes a flexible substrate, plural pixels provided on the substrate and each including a photoelectric conversion element, a scintillator stacked on the substrate, and a bending suppression member configured to suppress bending of the substrate. The bending suppression member has a rigidity that satisfies R≥X 2 /2Z L  wherein X is a pixel size, Z L  is a critical deformation amount of the pixel through bending of the substrate, and R is a radius of curvature of bending occurring in the substrate due to the weight of the scintillator.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of InternationalApplication No. PCT/JP2019/009954 filed Mar. 12, 2019, the disclosure ofwhich is incorporated herein by reference in its entirety. Further, thisapplication claims priorities from Japanese Patent Application No.2018-051691, filed Mar. 19, 2018, Japanese Patent Application No.2018-219697, filed Nov. 22, 2018, and Japanese Patent Application No.2019-022081, filed Feb. 8, 2019, the disclosures of which areincorporated herein by reference in their entirety.

TECHNICAL FIELD

Technology disclosed herein relates to a radiation detector, aradiographic imaging device, and a method of manufacturing a radiationdetector.

RELATED ART

The following technology is an example of known technology related to aradiographic imaging device. Japanese Patent Application Laid-Open(JP-A) No. 2012-173275 (Patent Document 1) describes a radiographicimage detection device equipped with a radiographic image detectiondevice body including a scintillator for converting radiation intofluorescence and a light detection section provided at theradiation-incident side of the scintillator, and also equipped with asupport member disposed at the radiation-incident side of theradiographic image detection device body to support an imaging subject.The light detection section includes a thin film section to detectfluorescence as an electrical signal, and a reinforcement memberprovided on the opposite side of the thin film section to thescintillator and joined to the support member.

Japanese National-Phase Publication No. 2017-532540 (Patent Document 2)describes a detection section including a first modular detector and asecond modular detector that are joined so as to be mutually connectedto one another. The first and second modular detectors are flexible. Areinforcement member is mounted on the opposite side to light receptionfaces of the first and second modular detectors, in a configuration inwhich the reinforcement member prevents bending of the modular detectorsin the vicinity of the reinforcement member mounting positions.

A known radiation detector employed in a radiographic imaging deviceincludes a substrate, plural pixels provided on the substrate, each ofthe pixels including a photoelectric conversion element, and ascintillator stacked on the substrate. In recent years flexiblematerials such as resin films are being employed as radiation detectorsubstrate materials. In cases in which the substrate is flexible, forexample, a concern arises that comparatively large localized bending ofthe substrate might occur due to the weight of the scintillator stackedon the substrate when the substrate is handled during processes tomanufacture the radiation detector. The photoelectric conversionelements configuring each pixel are configured from materials such asamorphous silicon that are brittle under bending stress. There isaccordingly a concern that the pixels might sustain damage weresignificant bending of the substrate to occur.

SUMMARY

An object of an aspect of technology disclosed herein is to reduce therisk of damage to pixels caused by a substrate bending due to the weightof a scintillator compared to cases in which a bending suppressionmember having a rigidity prescribed according to pixel size is not used.

A radiation detector according to a first aspect of technology disclosedherein includes a flexible substrate, plural pixels provided on thesubstrate and each including a photoelectric conversion element, ascintillator stacked on the substrate, and a bending suppression memberconfigured to suppress bending of the substrate. The bending suppressionmember has a rigidity that satisfies R≥X²/2Z_(L), wherein X is a pixelsize, Z_(L) is a critical deformation amount of the pixel throughbending of the substrate, and R is a radius of curvature of bendingoccurring in the substrate due to the weight of the scintillator.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view illustrating an example of a configurationof a radiographic imaging device according to an exemplary embodiment oftechnology disclosed herein.

FIG. 2 is a cross-section illustrating an example of a configuration ofa radiographic imaging device according to an exemplary embodiment oftechnology disclosed herein.

FIG. 3 is a diagram illustrating an example of an electricalconfiguration of a radiographic imaging device according to an exemplaryembodiment of technology disclosed herein.

FIG. 4 is a diagram illustrating an example of a state in which asubstrate according to an exemplary embodiment of technology disclosedherein has been bent into a circular arc shape.

FIG. 5A is a diagram illustrating an example of an external shape of apixel according to an exemplary embodiment of technology disclosedherein.

FIG. 5B is a diagram illustrating an example of an external shape of apixel according to an exemplary embodiment of technology disclosedherein.

FIG. 5C is a diagram illustrating an example of an external shape of apixel according to an exemplary embodiment of technology disclosedherein.

FIG. 6A is a cross-section illustrating an example of a method formanufacturing a radiation detector according to an exemplary embodimentof technology disclosed herein.

FIG. 6B is a cross-section illustrating an example of a method formanufacturing a radiation detector according to an exemplary embodimentof technology disclosed herein.

FIG. 6C is a cross-section illustrating an example of a method formanufacturing a radiation detector according to an exemplary embodimentof technology disclosed herein.

FIG. 6D is a cross-section illustrating an example of a method formanufacturing a radiation detector according to an exemplary embodimentof technology disclosed herein.

FIG. 7A is a cross-section illustrating an example of a configuration ofa radiation detector according to an exemplary embodiment of technologydisclosed herein.

FIG. 7B is a cross-section illustrating an example of a configuration ofa radiation detector according to an exemplary embodiment of technologydisclosed herein.

FIG. 8A is a cross-section illustrating an example of a configuration ofa radiation detector according to an exemplary embodiment of technologydisclosed herein.

FIG. 8B is a cross-section illustrating an example of a configuration ofa radiation detector according to an exemplary embodiment of technologydisclosed herein.

FIG. 8C is a cross-section illustrating an example of a configuration ofa radiation detector according to an exemplary embodiment of technologydisclosed herein.

FIG. 9 is a cross-section illustrating an example of a state in which asubstrate has bent due to the weight of a scintillator.

FIG. 10 is cross-section illustrating an example of a configuration of asubstrate according to an exemplary embodiment of technology disclosedherein.

FIG. 11A is a cross-section illustrating back scattering radiationgenerated inside a substrate containing a fine particle layer.

FIG. 11B is a cross-section illustrating back scattering radiationgenerated inside a substrate lacking a fine particle layer.

FIG. 12 is a cross-section illustrating an example of a configuration ofa radiation detector according to an exemplary embodiment of technologydisclosed herein.

FIG. 13 is a cross-section illustrating an example of a configuration ofa radiation detector according to an exemplary embodiment of technologydisclosed herein.

FIG. 14 is a cross-section illustrating an example of a configuration ofa radiation detector according to an exemplary embodiment of technologydisclosed herein.

FIG. 15 is a cross-section illustrating an example of a configuration ofa radiation detector according to an exemplary embodiment of technologydisclosed herein.

FIG. 16 is a cross-section illustrating an example of a configuration ofa radiation detector according to an exemplary embodiment of technologydisclosed herein.

FIG. 17 is a cross-section illustrating an example of a configuration ofa radiation detector according to an exemplary embodiment of technologydisclosed herein.

FIG. 18 is a cross-section illustrating an example of a configuration ofa radiation detector according to an exemplary embodiment of technologydisclosed herein.

FIG. 19 is a cross-section illustrating an example of a configuration ofa radiation detector according to an exemplary embodiment of technologydisclosed herein.

FIG. 20 is a cross-section illustrating an example of a configuration ofa radiation detector according to an exemplary embodiment of technologydisclosed herein.

FIG. 21 is a cross-section illustrating an example of a configuration ofa radiation detector according to an exemplary embodiment of technologydisclosed herein.

FIG. 22 is a cross-section illustrating an example of a configuration ofa radiation detector according to an exemplary embodiment of technologydisclosed herein.

FIG. 23 is a cross-section illustrating an example of a configuration ofa radiation detector according to an exemplary embodiment of technologydisclosed herein.

FIG. 24 is a cross-section illustrating an example of a configuration ofa radiation detector according to an exemplary embodiment of technologydisclosed herein.

FIG. 25 is a cross-section illustrating an example of a configuration ofa radiation detector according to an exemplary embodiment of technologydisclosed herein.

FIG. 26 is a cross-section illustrating an example of a configuration ofa radiation detector according to an exemplary embodiment of technologydisclosed herein.

FIG. 27 is a cross-section illustrating an example of a configuration ofa radiation detector according to an exemplary embodiment of technologydisclosed herein.

FIG. 28 is a cross-section illustrating an example of a configuration ofa radiation detector according to an exemplary embodiment of technologydisclosed herein.

FIG. 29 is a cross-section illustrating an example of a configuration ofa radiation detector according to an exemplary embodiment of technologydisclosed herein.

FIG. 30 is a cross-section illustrating an example of a configuration ofa radiation detector according to an exemplary embodiment of technologydisclosed herein.

FIG. 31 is a cross-section illustrating an example of a configuration ofa radiation detector according to an exemplary embodiment of technologydisclosed herein.

FIG. 32 is a cross-section illustrating an example of a configuration ofa radiation detector according to an exemplary embodiment of technologydisclosed herein.

FIG. 33 is a cross-section illustrating an example of a configuration ofa radiation detector according to an exemplary embodiment of technologydisclosed herein.

FIG. 34 is a cross-section illustrating an example of a configuration ofa radiation detector according to an exemplary embodiment of technologydisclosed herein.

FIG. 35 is a cross-section illustrating an example of a configuration ofa radiation detector according to an exemplary embodiment of technologydisclosed herein.

FIG. 36 is a cross-section illustrating an example of a configuration ofa radiation detector according to an exemplary embodiment of technologydisclosed herein.

FIG. 37 is a cross-section illustrating an example of a configuration ofa radiation detector according to an exemplary embodiment of technologydisclosed herein.

FIG. 38 is a cross-section illustrating an example of a configuration ofa radiation detector according to an exemplary embodiment of technologydisclosed herein.

FIG. 39 is a cross-section illustrating an example of a configuration ofa radiation detector according to an exemplary embodiment of technologydisclosed herein.

FIG. 40 is a plan view illustrating an example of a structure of abending suppression member according to an exemplary embodiment oftechnology disclosed herein.

FIG. 41 is a perspective view illustrating an example of a structure ofa bending suppression member according to an exemplary embodiment oftechnology disclosed herein.

FIG. 42 is a cross-section illustrating an example of a configuration ofa radiation detector according to an exemplary embodiment of technologydisclosed herein.

FIG. 43 is a plan view illustrating an example of a structure of abending suppression member according to an exemplary embodiment oftechnology disclosed herein.

FIG. 44 is a plan view illustrating an example of a structure of abending suppression member according to an exemplary embodiment oftechnology disclosed herein.

FIG. 45 is a cross-section illustrating an example of a configuration ofa radiographic imaging device according to an exemplary embodiment oftechnology disclosed herein.

FIG. 46 is a cross-section illustrating an example of a configuration ofa radiographic imaging device according to an exemplary embodiment oftechnology disclosed herein.

FIG. 47 is a cross-section illustrating an example of a configuration ofa radiographic imaging device according to an exemplary embodiment oftechnology disclosed herein.

DETAILED DESCRIPTION

Explanation follows regarding examples of exemplary embodiments oftechnology disclosed herein, with reference to the drawings. Note thatthe same or equivalent configuration elements and portions are allocatedthe same reference numerals in each of the drawings.

First Exemplary Embodiment

FIG. 1 is a perspective view illustrating an example of configuration ofa radiographic imaging device 10 according to an exemplary embodiment oftechnology disclosed herein. The radiographic imaging device 10 employsa portable electronic cassette format. The radiographic imaging device10 is configured including a radiation detector 30 (flat panel detector(FPD)), a control unit 12, a support plate 16, and a case 14 housing theradiation detector 30, the control unit 12, and the support plate 16.

The case 14 has, for example, a monocoque structure configured fromcarbon fiber reinforced plastic, which X-ray radiation and the likereadily permeates, and is lightweight and highly durable. Radiationemitted from a radiation source (not illustrated in the drawings) andtransmitted through an imaging subject (not illustrated in the drawings)is incident to a radiation-incident face 15 configuring an upper face ofthe case 14. Inside the case 14, the radiation detector 30 and thesupport plate 16 are arranged in this sequence from theradiation-incident face 15 side.

The support plate 16 is fixed to the case 14, and supports a circuitboard 19 (see FIG. 2) to which is mounted an integrated circuit chip forperforming signal processing and the like. The control unit 12 isarranged at an end portion inside the case 14. The control unit 12 isconfigured including a battery (not illustrated in the drawings) and acontroller 29 (see FIG. 3).

FIG. 2 is a cross-section illustrating an example of a configuration ofthe radiographic imaging device 10. The radiation detector 30 includes aflexible substrate 34, plural pixels 41 that are provided on a frontsurface of the substrate 34 and that each include a photoelectricconversion element 36 (see FIG. 3), and a scintillator 32 and a bendingsuppression member 60 to suppress bending of the substrate 34, bothstacked on the substrate 34.

The substrate 34 is a flexible substrate that is capable of bending. Inthe present specification, reference to the substrate 34 being flexiblemeans that when the rectangular substrate 34 is fixed at one side out ofits four sides, then due to the weight of the substrate 34, a height ata position 10 cm away from the fixed side of the substrate 34 will be atleast 2 mm lower than the height of the fixed side. For example, a resinsubstrate, a metal foil substrate, or a thin glass sheet having athickness of about 0.1 mm may be employed as the material of thesubstrate 34. A resin film such as XENOMAX (registered trademark) or thelike that is a highly heat-resistant polyimide film is particularlypreferably employed therefor. Employing a resin film as the material ofthe substrate 34 enables a reduction in weight and a reduction in costof the radiation detector 30 to be achieved compared to cases in which aglass substrate is employed as the material of the substrate 34, andfurthermore, the risk of impact damage to the substrate 34 can also bereduced. The plural pixels 41 are respectively provided on a firstsurface S1 of the substrate 34.

The thickness of the substrate 34 depends on the hardness, size, and thelike of the substrate 34, and may be any thickness that enables thedesired flexibility to be achieved. In cases in which the substrate 34is configured including a base member made from a resin material, thethickness of the substrate 34 is, for example, preferably from 5 μm to125 μm, and is more preferably from 20 μm to 50 μm.

Note that the coefficient of thermal expansion (CTE) of the substrate 34in a temperature range of from 300° C. to 400° C. is preferablyapproximately the same as the coefficient of thermal expansion of thematerial configuring the photoelectric conversion element 36 (amorphoussilicon, for example) (±approximately 5 ppm/K), and specifically ispreferably not more than 20 ppm/K. Moreover, a heat shrinkage ratio in amachine direction (MD) of the substrate 34 at 400° C. and at a thicknessof 25 μm is preferably not more than 0.5%. Moreover, the substrate 34preferably does not have a transition point in a temperature range offrom 300° C. to 400° C., as is typical of an ordinary polyimide, andpreferably has a modulus of elasticity at 500° C. of not less than 1GPa. The substrate 34 with the above characteristics is able towithstand thermal processing when forming the pixels 41 on the substrate34, and enables the pixels 41 to be formed on the substrate 34 in anappropriate manner.

Moreover, in cases in which the substrate 34 is configured including abase member formed from a resin material such as a polyimide or thelike, as illustrated in FIG. 10, the base member made from the resinmaterial preferably includes a fine particle layer 34L containing pluralfine particles 34P made from an inorganic material and having a meanparticle size of from 0.05 μm to 2.5 μm. Moreover, the fine particlelayer 34L is preferably provided on a second surface S2 of the substrate34, this being on the opposite side of the substrate 34 to the firstsurface S1 provided with the pixels 41. Namely, the fine particles 34Pare preferably present more toward the second surface S2 side of thesubstrate 34. The fine particles 34P may sometimes cause indentationsand protrusions on the front surface of the substrate 34, making itdifficult to form the pixels 41 on the front surface of the fineparticle layer 34L. Arranging the fine particle layer 34L on the secondsurface S2 side of the substrate 34 enables the flatness of the firstsurface S1 to be secured, making it easier to form the pixels 41.

The material of the fine particles 34P is preferably an inorganicmaterial including an element having an atomic number that is greaterthan the atomic number of each element configuring the base member ofthe substrate 34, but that is not more than 30. For example, in cases inwhich the base member of the substrate 34 is configured from a resinmaterial such as an polyimide or the like including C, H, O, and N, thefine particles 34P are preferably configured of an inorganic materialincluding an element that has an atomic number greater than the atomicnumbers of the elements configuring the resin material (i.e. C, H, O,and N) but that is not more than 30. Specific examples of such fineparticles 34P include SiO₂ that is an oxide of silicon of atomic number14, MgO that is an oxide of Mg of atomic number 12, Al₂O₃ that is anoxide of Al of atomic number 13, and TiO₂ that is an oxide of Ti ofatomic number 22. XENOMAX (registered trademark) is a specific exampleof a resin sheet having the characteristics listed above and containinga fine particle layer 34L.

Note that the above thicknesses in the present exemplary embodiment aremeasured using a micrometer. The coefficient of thermal expansion ismeasured according to JIS K7197:1991. In this measurement, test piecesare cut from a main face of the substrate 34 while changing the anglethereof by 15 degrees each time, the coefficient of thermal expansion ismeasured for each of the cut test pieces, and the highest value obtainedis taken to be the coefficient of thermal expansion of the substrate 34.The measurements of the coefficient of thermal expansion in the machinedirection (MD) and the transverse direction (TD) are performed at 10° C.intervals over a range of from −50° C. to 450° C. with ppm/° C.converted into ppm/K. A TMA4000S instrument made by MAC Science Co.,Ltd. is employed to measure the coefficient of thermal expansion using asample length of 10 mm, a sample width of 2 mm, an initial load of 34.5g/mm², a speed of temperature increase of 5° C./min, and an argonatmosphere. The modulus of elasticity is measured according toK7171:2016. Note that in this measurement, test pieces are cut from amain face of the substrate 34 while changing the angle thereof by 15degrees each time, a stretch test is performed on each of the cut testpieces, and the highest value obtained is taken to be the modulus ofelasticity of the substrate 34.

The scintillator 32 is stacked on the first surface S1 side of thesubstrate 34. The scintillator 32 contains phosphors for convertingirradiated radiation into light. The scintillator 32 is configured, forexample, by an aggregation of columnar crystals including thallium-dopedcaesium iodide (CsI:Tl). The columnar crystals of CsI:Tl can be directlyformed on the substrate 34 using, for example, a vapor-phase growthmethod. Note that the columnar crystals of CsI:Tl may be formed on aseparate substrate from the substrate 34, and then stuck to thesubstrate 34. Moreover, terbium-doped gadolinium oxysulfide (Gd₂O₂S:Tb)may be employed as the material of the scintillator 32. Each of therespective photoelectric conversion elements 36 (see FIG. 3) configuringthe plural pixels 41 generates an electrical charge based on the lightemitted from the scintillator 32.

A surface S3 of the scintillator 32 on the opposite side to a surface S6that contacts the substrate 34, and a surface S4 of the scintillator 32that intersects with the surface S3, are covered by a reflective film50. The reflective film 50 has a function to reflect light generated inthe scintillator 32 toward the substrate 34 side. Al₂O₃ may, forexample, be employed as the material of the reflective film 50. Thereflective film 50 covers the surface S3 and the surface S4 of thescintillator 32, and also covers the substrate 34 at portions in thevicinity of the scintillator 32. Note that the reflective film 50 may beomitted in cases in which a radiographic image of the desired qualitycan be obtained with the radiographic imaging device 10 withoutproviding the reflective film 50.

In the present exemplary embodiment, the substrate 34 is arranged at theradiation-incident side and the radiographic imaging device 10 employsan irradiation side sampling (ISS) imaging method. Adopting theirradiation side sampling method enables the distance been positions ofintense light emission in the scintillator 32 and the pixels 41 to beshortened compared to when employing a penetration side sampling (PSS)method, in which the scintillator 32 is arranged at theradiation-incident side. This thereby enables radiographic images to beobtained with higher resolution. Note that the radiographic imagingdevice 10 may employ penetration side sampling.

The support plate 16 is arranged at the opposite side of thescintillator 32 to the radiation-incident side. A gap is providedbetween the support plate 16 and the scintillator 32. The support plate16 is fixed to side portions of the case 14. The circuit board 19 isprovided on the surface of the support plate 16 on the opposite side tothe scintillator 32. The circuit board 19 is mounted with circuitries ofa signal processor 26 for generating image data, an image memory 28 forstoring the image data generated by the signal processor 26, and thelike.

The circuit board 19 and the substrate 34 are electrically connectedtogether through a flexible cable 20 printed on a flexible printedcircuit (FPC) and a tape carrier package (TCP) or a chip-on-film (COF).Charging amplifiers 24 for converting electrical charge read from thepixels 41 into electrical signals are mounted on the cable 20. A gateline driver 22 (see FIG. 3) that is electrically connected to thecircuit board 19 and the substrate 34 is mounted to a separate flexibleprinted circuit not illustrated in FIG. 2.

The bending suppression member 60 is stacked on the second surface S2side of the substrate 34 on the opposite side to the first surface S1.The bending suppression member 60 has the role of imparting thesubstrate 34 with the necessary rigidity for the substrate 34 to supportthe scintillator 32. Namely, providing the bending suppression member 60suppresses the substrate 34 from bending due to the weight of thescintillator 32 compared to cases in which the bending suppressionmember 60 is omitted. The bending suppression member 60 extends over awider range than an extension range of the scintillator 32. Namely, asurface area of the bending suppression member 60 is larger than asurface area of the scintillator 32 in plan view, and the scintillator32 is arranged at the inside of the extension range of the bendingsuppression member 60. Thus, planar direction end portions of thebending suppression member 60 are positioned to the outside of planardirection end portions of the scintillator 32. This enhances the effectof suppressing the substrate 34 from bending due to the weight of thescintillator 32. The substrate 34 includes a connection region 80 wherethe flexible cable 20 is connected to an outer peripheral portion of thesubstrate 34. The bending suppression member 60 is provided in a regioncovering at least a portion of the connection region 80 and alsocovering the scintillator 32. Since the substrate 34 has a tendency tobend even in the connection region 80 where the flexible cable 20 isconnected, providing the bending suppression member 60 in the regioncovering at least a portion of the connection region 80 enables bendingin the connection region 80 of the substrate 34 to be suppressed.

The bending suppression member 60 preferably has a higher rigidity thanthat of the substrate 34 from the perspective of being able to suppressbending of the substrate 34. The bending suppression member 60 ispreferably a member employing a material having a bending elasticmodulus from 1000 MPa to 3500 MPa. By configuring the bendingsuppression member 60 from a material having a bending elastic modulusof 1000 MPa or greater, functionality is effectively exhibited by thebending suppression member 60 to suppress bending of the substrate 34.Configuring the bending suppression member 60 from a material having abending elastic modulus of 3500 MPa or lower means that, for example,after the bending suppression member 60 has been attached to thesubstrate 34 in a manufacturing process of the radiation detector 30,when detaching a support body (not illustrated in the drawings)supporting the substrate 34 from the substrate, the support body can beeasily detached from the substrate 34 by appropriately bending thesubstrate 34. Note that the method employed to measure the bendingelastic modulus may be the measurement method defined in JIS K7171:2016. Moreover, the bending rigidity of the bending suppressionmember 60 is preferably from 3600 Pa·cm⁴ to 196000 Pa·cm⁴. The thicknessof the bending suppression member 60 is preferably approximately 0.1 mm.

The coefficient of thermal expansion of the bending suppression member60 is preferably from 30 ppm/K to 80 ppm/K. Moreover, the coefficient ofthermal expansion of the bending suppression member 60 is preferablyclose to the coefficient of thermal expansion of the scintillator 32.Specifically, a ratio of the coefficient of thermal expansion C2 of thebending suppression member 60 against the coefficient of thermalexpansion C1 of the scintillator 32 (C2/C1) is preferably from 0.5 to 2.Making the coefficient of thermal expansion of the bending suppressionmember 60 satisfy the conditions listed above enables the risk of thesubstrate 34 and the scintillator 32 detaching from each other, such aswhen heating or when heat is generated, to be suppressed. For example,the coefficient of thermal expansion of the scintillator 32 is 50 ppm/Kin cases in which the scintillator 32 is configured mainly from CsI:Tl.In such cases, the following materials may be employed as the materialof the bending suppression member 60: polyvinyl chloride (PVC) having acoefficient of thermal expansion of from 60 ppm/K to 80 ppm/K, acrylichaving a coefficient of thermal expansion of from 70 ppm/K to 80 ppm/K,polyethylene terephthalate (PET) having a coefficient of thermalexpansion of from 65 ppm/K to 70 ppm/K, polycarbonate (PC) having acoefficient of thermal expansion of 65 ppm/K, TEFLON (registeredtrademark) having a coefficient of thermal expansion of from 45 ppm/K to70 ppm/K, or the like. In consideration of the above bending elasticmodulus, the material of the bending suppression member 60 preferably isa material including at least one out of acrylic, PET, or PC.

Other candidate materials that may be employed for the bendingsuppression member 60 include, for example, resins of polyphenylenesulfide (PPS), polyarylate (PAR), polysulfone (PSF), polyether sulfone(PES), polyetherimide (PEI), polyamide-imide (PAI), polyether etherketone (PEEK), phenol resin, polytetrafluoroethylene,polychlorotrifluoroethylene, silicone resin, polyethylene naphthalate(PEN), and the like. A metal such as aluminum, iron, or an alloy thereofmay also be employed as the material of the bending suppression member60. A layered body configured by stacking layers of resin and metal mayalso be employed as the material of the bending suppression member 60.The surface S5 of the bending suppression member 60 on the opposite sideto the face contacting the substrate 34 is stuck to an inner wall of thecase 14 with a bonding layer 18 interposed therebetween.

FIG. 3 is a diagram illustrating an example of an electricalconfiguration of the radiographic imaging device 10. Plural pixels 41are arranged in a matrix formation on the first surface S1 of thesubstrate 34. Each of the pixels 41 includes a photoelectric conversionelement 36 and a thin film transistor (TFT) 42. The photoelectricconversion element 36 generates electrical charge according to the lightemitted from the scintillator 32. The TFT 42 serves as a switchingelement that is switched to an ON state in order to read the electricalcharge generated in the photoelectric conversion element 36. Thephotoelectric conversion element 36 may, for example, be a photodiodeconfigured from amorphous silicon.

Gate lines 43 and signal lines 44 are provided on the first surface S1of the substrate 34. The gate lines 43 extend in one direction (a rowdirection) that the pixels 41 are arrayed along. The signal lines 44extend in a direction (a column direction) intersecting with theextension direction of the gate lines 43. The pixels 41 are provided soas to correspond to the respective intersection portions between thegate lines 43 and the signal lines 44.

Each of the gate lines 43 is connected to the gate line driver 22. Thegate line driver 22 performs reading of the electrical chargeaccumulated in the pixels 41 in response to a control signal suppliedfrom the controller 29. Each of the signal lines 44 is connected to acharging amplifier 24. The charging amplifiers 24 are providedcorresponding to each of the plural signal lines 44. The chargingamplifiers 24 generate electrical signals based on the electrical chargeread from the pixels 41. The output terminals of the charging amplifiers24 are connected to the signal processor 26. Based on the controlsignals supplied from the controller 29, the signal processor 26generates image data by performing specific processing on the electricalsignals supplied from the charging amplifiers 24. The image memory 28 isconnected to the signal processor 26. The image memory 28 stores theimage data generated by the signal processor 26 based on the controlsignals supplied from the controller 29.

The controller 29 has a wired or wireless connection to a radiationsource via a communication section (not illustrated in the drawings),performs communication with a console (not illustrated in the drawings),and controls operation of the radiographic imaging device 10 bycontrolling the gate line driver 22, the signal processor 26, and theimage memory 28. The controller 29 may have a configuration including,for example, a microcomputer. Note that the gate line driver 22 is anexample of a reading section of technology disclosed herein. The signalprocessor 26 is an example of a generation section of technologydisclosed herein.

Explanation follows regarding an example of operation of theradiographic imaging device 10. When radiation emitted from theradiation source (not illustrated in the drawings) and transmittedthrough an imaging subject is incident through the radiation-incidentface 15 of the radiographic imaging device 10, the scintillator 32absorbs the radiation and emits visible light. The photoelectricconversion elements 36 configuring the respective pixels 41 convert thelight emitted from the scintillator 32 into electrical charge. Theelectrical charge generated by each of the photoelectric conversionelements 36 is accumulated in the corresponding pixel 41. The amount ofelectrical charge generated by the photoelectric conversion element 36is reflected in a pixel value of the corresponding pixel 41.

In order to generate a radiographic image, the gate line driver 22supplies a gate signal to the TFTs 42 through gate lines 43 based on acontrol signal supplied from the controller 29. The TFTs 42 are switchedto the ON state by the gate signal in row units. Due to the TFTs 42being switched to the ON state, the electrical charge accumulated ineach of the pixels 41 is read through the corresponding signal line 44,and is supplied to the corresponding charging amplifier 24. The chargingamplifiers 24 generate electrical signals based on the electricalcharges read from the signal lines 44 and supply the generatedelectrical signals to the signal processor 26.

The signal processor 26 is equipped with plural sample-and-holdcircuits, a multiplexer, and an analogue-to-digital converter (none ofwhich are illustrated in the drawings). The plural sample-and-holdcircuits are provided so as to correspond to each of the respectiveplural signal lines 44. The electrical signals supplied from thecharging amplifiers 24 are held in the sample-and-hold circuits. Theelectrical signals held in the individual sample-and-hold circuits areeach input to the analogue-to-digital converter through the multiplexerto be converted into digital signals. The signal processor 26 generates,as image data, data in which the digital signals generated by theanalogue-to-digital converter are associated with information about thepositions of the respective pixels 41, and supplies this image data tothe image memory 28. The image memory 28 stores the image data generatedby the signal processor 26.

Due to the flexibility of the substrate 34, there is a concern thatcomparatively large localized bending might occur in the substrate 34due to the weight of the scintillator 32 when, for example, thesubstrate 34 is handled during processes to manufacture the radiationdetector 30. There is a concern that the pixels 41 provided on the frontsurface of the substrate 34 might sustain damage were significantbending of the substrate 34 to occur.

FIG. 4 is a diagram illustrating a state in which the substrate 34 hasbeen bent into a circular arc shape. In FIG. 4, R indicates the radiusof curvature of the bending occurring in the substrate 34, and Xindicates the size of one of the pixels 41 formed on the substrate 34.Namely, a distance between a point A at one end portion of the pixel 41and a point B at the other end portion of the pixel 41 (a length of linesegment AB) corresponds to the size X of the pixel 41.

Note that the size of the photoelectric conversion element 36 may beapplied as the size of the pixel 41. Moreover, the length of a maximumlength portion of the pixel 41 (the photoelectric conversion element 36)may be applied as the size of the pixel 41. For example, as illustratedin FIG. 5A, FIG. 5B, and FIG. 5C, in cases in which the external shapeof the pixel 41 (the photoelectric conversion element 36) is a polygonalshape such as a square, rectangle, regular hexagon, or the like, thenthe length of a diagonal line of the pixel 41 may be applied as the sizeX of the pixel 41. Alternatively, the length of one side of the pixel 41may be applied as the size X of the pixel 41 (the photoelectricconversion element 36). In such cases, if the pixel 41 has both a longside and a short side, such as when the external shape of the pixel 41is a rectangle, then the length of the long side is preferably appliedas the size of the pixel 41 (photoelectric conversion element 36).

Z in FIG. 4 is a deformation amount of the pixel 41 due to bending ofthe substrate 34. Namely, the deformation amount Z corresponds to adistance (length of a line segment BC) between a tangent L to one endportion of the pixel 41 (point A) and the other end portion of the pixel41 (point B). θ in FIG. 4 corresponds to a central angle of a sectorincluding an arc AB.

The size X of the pixel 41 corresponds to the length of the chord AB ofthe circular arc of the substrate 34 when bent into a circular arcshape. Thus the size X of the pixel 41 can be expressed by the followingEquation (1).

X=2R sin(θ/2)  (1)

The following Equation (2) can be derived therefrom since ∠BAC is θ/2.

sin(θ/2)=Z/X  (2)

Substituting Equation (2) in Equation (1) enables the following Equation(3) and Equation (4) to be derived.

X=2R×Z/X  (3)

R=X ²/2Z  (4)

If the maximum value of the deformation amount Z at which the pixel 41is not damaged (also referred below to as the critical deformationamount) is denoted Z_(L), then the risk of damaging the pixel 41 can bereduced by limiting the range of the radius of curvature R when bendingthe substrate 34 to the range given in Equation (5) below.

R≥X ²/2Z _(L)  (5)

For example, if the size X of the pixel 41 is 150 μm, and the criticaldeformation amount Z_(L) of the pixel 41 is 0.05 μm, then the risk ofdamaging the pixel 41 can be reduced by limiting the radius of curvatureR to not less than 225 mm when bending the substrate 34.

The portions more susceptible to damage are portions of thicker layerthickness and portions of higher brittleness. For example, in cases inwhich the photoelectric conversion element 36 includes a photodiodeformed in an amorphous silicon layer, then the amorphous silicon layeris more susceptible to damage. In such cases the thickness of theamorphous silicon layer is approximately from 0.5 μm to 2.5 μm, withthis being a particularly thick thickness in the pixel 41, and thecritical deformation amount Z_(L) is small.

In the radiation detector 30 according to the present exemplaryembodiment, the rigidity of the bending suppression member 60 is setsuch that, in a fixed state to end portions of the substrate 34, theradius of curvature R of bending that occurs in the substrate 34 due tothe weight of the scintillator 32 satisfies Equation (5). In otherwords, the rigidity of the bending suppression member 60 is adjustedsuch that, in a fixed state to end portions of the substrate 34, theradius of curvature R of the bending that occurs in the substrate 34 dueto the weight of the scintillator 32 satisfies Equation (5). Namely, therigidity of the bending suppression member 60 is prescribed according tothe size of the pixels 41. Adopting this approach enables the risk ofthe pixels 41 being damaged by bending of the substrate 34 due to theweight of the scintillator 32 when, for example, the substrate 34 ishandled during processes to manufacture the radiation detector 30, to bereduced in comparison to cases in which Equation (5) is not satisfied.For example, since the permitted radius of curvature R becomes largerthe greater the size X of the pixel 41, a bending suppression member 60having a higher rigidity is employed.

The rigidity of the bending suppression member 60 may, for example, beadjusted using the thickness, density, elastic modulus, or the like ofthe bending suppression member 60. Moreover, the rigidity of the bendingsuppression member 60 may also be adjusted by the selection of thematerial configuring the bending suppression member 60.

Explanation follows regarding a method of manufacturing the radiationdetector 30. FIG. 6A to FIG. 6D are cross-sections illustrating anexample of a method of manufacturing the radiation detector 30.

Firstly, the plural pixels 41 are formed on the first surface S1 of thesubstrate 34 (FIG. 6A). Note that formation of the pixels 41 may beperformed in a state in which the substrate 34 is supported by a supportbody (not illustrated in the drawings) to support the substrate 34.

Next, the bending suppression member 60 is stuck to the second surfaceS2 of the substrate 34 on the opposite side to the first surface S1 ofthe substrate 34 (FIG. 6B). The bending suppression member 60 has arigidity such that the radius of curvature R of bending that occurs inthe substrate 34 due to the weight of the scintillator 32 satisfiesEquation (5). For example, the rigidity of the bending suppressionmember 60 is set higher the greater the size X of the pixels 41.

Next, the scintillator 32 is formed on the first surface S1 of thesubstrate 34 (FIG. 6C). The scintillator 32 may be formed using, forexample, a vapor-phase growth method, so as to directly grow columnarcrystals of Tl-doped CsI on the substrate 34. Note that columnarcrystals of CsI:Tl may be formed on a different substrate to thesubstrate 34 and then stuck to the substrate 34. Alternatively,Gd₂O₂S:Tb (terbium-doped gadolinium oxysulfide) may be employed as thematerial of the scintillator 32.

The reflective film 50 is then formed so as to cover the surface S3 ofscintillator 32 on the opposite side to the surface S6 contacting thesubstrate 34, and to cover the surface S4 that intersects with thesurface S3 (FIG. 6D). Al₂O₃ may, for example, be employed as thematerial of the reflective film 50. The reflective film 50 is formed soas to cover the substrate 34 at portions in the vicinity of thescintillator 32.

In the radiation detector 30 and the radiographic imaging device 10according to the exemplary embodiment of technology disclosed herein,the rigidity of the bending suppression member 60 is set such that theradius of curvature R of bending that occurs in the substrate 34 due tothe weight of the scintillator 32 satisfies Equation (5). Thus theradius of curvature R of bending that occurs in the substrate 34 due tothe weight of the scintillator 32 is limited to the range of Equation(5). This thereby enables the risk of the pixels 41 being damaged when,for example, the substrate 34 is handled during processes to manufacturethe radiation detector 30 to be reduced, even when bending occurs in thesubstrate 34 due to the weight of the scintillator 32, compared to casesin which the technology disclosed herein is not applied.

FIG. 11A and FIG. 11B are cross-sections illustrating examples of apartial configuration of a radiographic imaging device 10 in which anISS method is applied as the radiation sampling method. FIG. 11A andFIG. 11B each illustrate a case in which the substrate 34 is configuredincluding a base member made from a resin material such as a polyimideor the like. FIG. 11A illustrates a case in which the substrate 34contains the fine particle layer 34L, and FIG. 11B illustrates a case inwhich the substrate 34 does not contain a fine particle layer. In casesin which an ISS method is applied, from out of the substrate 34 and thescintillator 32 it is the substrate 34 that is arranged at theradiation-incident face 15 side of the case 14. Namely, the radiation Rincident to the radiation-incident face 15 is transmitted through thesubstrate 34 before being incident to the scintillator 32.

When the radiation is incident to the substrate 34 containing a resinmaterial with a configuration including elements having comparativelysmall atomic numbers, such as C, H, O, N, etc., a comparatively largeamount of back scattering radiation Rb is generated by the Comptoneffect, which could leak out toward an imaging subject 200. Asillustrated in FIG. 11A, by providing the substrate 34 with the fineparticle layer 34L that includes fine particles 34P configured frominorganic material including an element that has an atomic numbergreater than the atomic numbers of the elements configuring the resinmaterial (i.e. C, H, O, and N), back scattering radiation Rb generatedin the substrate 34 can be absorbed by the fine particle layer 34L. Thisenables the amount of back scattering radiation Rb leakage to theimaging subject 200 side to be suppressed in comparison to cases inwhich the substrate 34 does not include a fine particle layer (see FIG.11B). Note that the higher the atomic numbers of the elementsconfiguring the fine particles 34P, the greater the effect of absorbingthe back scattering radiation Rb increases. However, the amount ofradiation absorbed also increases and thus the amount of radiationreaching the scintillator 32 decreases. The atomic numbers of theelements configuring the fine particles 34P are thus preferably nothigher than 30.

Although an example has been described of a case in which the bendingsuppression member 60 is provided on the second surface S2 side of thesubstrate 34 in the exemplary embodiment described above, the technologydisclosed herein is not limited this approach. For example, asillustrated in FIG. 7A, the bending suppression member 60 may be stackedon the surface S3 side of the scintillator 32 that is the opposite sideto the surface S6 in contact with the substrate 34. Adopting such aconfiguration enables substantially the same advantageous effects to beobtained to cases in which the bending suppression member 60 is providedon the second surface S2 side of the substrate 34.

Moreover, as illustrated in FIG. 7B, the bending suppression member 60may be stacked on both the second surface S2 side of the substrate 34and on the surface S3 side of the scintillator 32 that is the oppositeside to the surface S6 in contact with the substrate 34. Stacking thebending suppression member 60 on at least one side from out of thesecond surface S2 side of the substrate 34 or the surface S3 side of thescintillator 32 that is the opposite side to the surface S6 in contactwith the substrate 34 enhances the bending suppression effect exhibitedby the bending suppression member 60. Moreover, as illustrated in FIG.7B, stacking a bending suppression member 60 on both the second surfaceS2 side of the substrate 34 and the surface S3 side of the scintillator32 enables the bending suppression effect exhibited by the bendingsuppression member 60 to be further enhanced, enabling the risk of thepixels 41 being damaged by bending of the substrate 34 to be reducedfurther. In cases in which bending suppression members 60 are stacked onboth the second surface S2 side of the substrate 34 and the surface S3side of the scintillator 32, the bending suppression member 60 stackedon the second surface S2 side of the substrate 34, this being theradiation-incident side, preferably absorbs a lower amount of radiationthan the bending suppression member 60 stacked on the surface S3 side ofthe scintillator 32.

Second Exemplary Embodiment

FIG. 8A is a cross-section illustrating an example of a configuration ofa radiation detector 30A according to a second exemplary embodiment oftechnology disclosed herein. The radiation detector 30A differs from theradiation detector 30 according to the first exemplary embodiment in thepoint that reinforcement members 70 are further included in order toreinforce the bending suppression effect of the bending suppressionmember 60.

In the configuration illustrated in FIG. 8A, the bending suppressionmember 60 is provided on the second surface S2 side of the substrate 34,and the reinforcement member 70 is provided on the surface S5 side ofthe bending suppression member 60, this being on the opposite side tothe surface of the bending suppression member 60 contacting thesubstrate 34. The reinforcement members 70 are provided in regionsstraddling planar direction end portions (outer edges, edges) 32E of thescintillator 32. Namely, the reinforcement members 70 are provided tothe bending suppression member 60 on the surface S5 side of the bendingsuppression member 60 in a state straddling a boundary between regionswhere the scintillator 32 is present and regions were the scintillator32 is not present. The reinforcement members 70 preferably have a higherrigidity than that of the substrate 34 from the perspective ofreinforcing the bending suppression effect of the bending suppressionmember 60. Preferable ranges for the bending elastic modulus and thecoefficient of thermal expansion of the reinforcement members 70 are thesame as those for the bending suppression member 60. The reinforcementmembers 70 may, for example, be configured from the same material as thebending suppression member 60, or may be configured from a materialhaving a higher rigidity than that of the bending suppression member 60.

FIG. 9 is a cross-section illustrating an example of a state in whichthe substrate 34 has bent due to the weight of the scintillator 32. Asillustrated in FIG. 9, at regions of the substrate 34 over which thescintillator 32 extends, the amount of bending of the substrate 34 iscomparatively small due to the rigidity of the scintillator 32. However,at the portions of the substrate 34 corresponding to the end portions32E of the scintillator 32, the amount of bending of the substrate 34 iscomparatively large. At the portions where the amount of bending of thesubstrate 34 is large, the risk of the pixels 41 being damaged is higherthan at portions where the amount of bending is small.

In the radiation detector 30A according to the second exemplaryembodiment of the technology disclosed herein, the reinforcement members70 are provided in regions straddling the end portions 32E of thescintillator 32 in order to reinforce the bending suppression effect ofthe bending suppression member 60. This enables the bending of theportions of the substrate 34 corresponding to the end portions 32E ofthe scintillator 32 to be suppressed compared to cases in which thereinforcement members 70 are not provided. Thus the risk of the pixels41 being damaged can be reduced compared to cases in which thereinforcement members 70 are not provided.

Note that as illustrated in FIG. 8B, the reinforcement members 70 may beprovided on the second surface S2 of the substrate 34 in cases in whichthe bending suppression member 60 is provided on the surface S3 of thescintillator 32 on the opposite side to the surface S6 in contact withthe substrate 34. Moreover, as illustrated in FIG. 8C, the reinforcementmembers 70 may be provided on the surface S5 of the bending suppressionmember 60 on the opposite side to the side of the face in contact withthe substrate 34 in cases in which the bending suppression members 60are provided on both the second surface S2 of the substrate 34 and onthe surface S3 of the scintillator 32. In either of the configurationsillustrated in FIG. 8B and FIG. 8C, the reinforcement members 70 areprovided in regions straddling the end portions (outer edges, edges) 32Eof the scintillator 32. Namely, in the configuration illustrated in FIG.8B, the reinforcement members 70 are provided to the substrate 34 on thesecond surface S2 side of the substrate 34 in a state straddlingboundaries between the region where the scintillator 32 is present andregions where the scintillator 32 is not present. In the configurationillustrated in FIG. 8C, the reinforcement members 70 are provided to thebending suppression member 60 on the surface S5 side of the bendingsuppression member 60 in a state straddling boundaries between theregion where the scintillator 32 is present and regions where thescintillator 32 is not present.

Third Exemplary Embodiment

FIG. 12 is a cross-section illustrating an example of a configuration ofa radiation detector 30B according to a third exemplary embodiment oftechnology disclosed herein. The radiation detector 30B includes abuffer layer 90 provided between the substrate 34 and the scintillator32. The buffer layer 90 has a coefficient of thermal expansion lyingbetween the coefficient of thermal expansion of the substrate 34 and thecoefficient of thermal expansion of the scintillator 32. A polyimidefilm or a parylene film may be employed, for example, as the bufferlayer 90. In cases in which XENOMAX (registered trademark) is employedas the material of the substrate 34, there is a larger differencebetween the coefficients of thermal expansion of the substrate 34 andthe scintillator 32 than in cases in which, for example, a glasssubstrate is employed as the substrate 34. Thermal stress acting at theinterface between the substrate 34 and the scintillator 32 wouldaccordingly be excessive. Providing the buffer layer 90 between thesubstrate 34 and the scintillator 32 enables such thermal stress to besuppressed from acting at the interface between the substrate 34 and thescintillator 32.

Other Exemplary Embodiments

FIG. 13 to FIG. 33 are each cross-sections illustrating examples ofinstallation embodiments of the bending suppression member 60 in casesin which the bending suppression member 60 is stacked on the side of thesurface of the scintillator 32 on the opposite side to the surface incontact with the substrate 34. In FIG. 13 to FIG. 33, a region whereplural pixels 41 are provided on the substrate 34 is denoted a pixelregion 41A.

In cases in which the scintillator 32 is formed using a vapor depositionmethod, as illustrated in FIG. 13 to FIG. 33, the scintillator 32 isformed with a slope with a gradually decreasing thickness on progressiontoward an outer edge thereof. In the following explanation, a centralregion of the scintillator 32 where the thickness may be regarded assubstantially constant if manufacturing error and measurement error areignored is referred to as a central portion 33A. Moreover, an outerperipheral region of the scintillator 32 where the thickness is, forexample, not more than 90% of the average thickness of the centralportion 33A of the scintillator 32 is referred to as a peripheral edgeportion 33B. Namely, the scintillator 32 includes a sloping face thatslopes with respect to the substrate 34 at the peripheral edge portion33B.

As illustrated in FIG. 13 to FIG. 33, an adhesion layer 51, a reflectivefilm 50, a bonding layer 52, a protective layer 53, and a bonding layer54 may be provided between the scintillator 32 and the bendingsuppression member 60.

The adhesion layer 51 covers the entire front surface of thescintillator 32, including the central portion 33A and the peripheraledge portion 33B of the scintillator 32. The adhesion layer 51 includesa function to fix the reflective film 50 to the scintillator 32. Theadhesion layer 51 preferably has light-transmitting properties. Examplesof materials that may be employed for the adhesion layer 51 includeacrylic-based adhesives, hot-melt-based adhesives, silicone-basedbonding agents, and the like. Examples of acrylic-based adhesivesinclude, for example, urethane acrylates, acrylic resin acrylates, epoxyacrylates, and the like. Examples of hot-melt-based adhesives includethermoplastic plastics such as copolymer resins of ethylene vinylacetate (EVA), copolymer resins of ethylene and acrylic acid (EAA),copolymer resins of ethylene and ethyl acrylate (EEA), copolymers ofethylene/methyl methacrylate (EMMA), and the like. The thickness of theadhesion layer 51 is preferably from 2 μm to 7 μm. Making the thicknessof the adhesion layer 51 not less than 2 μm enables the effect of fixingthe reflective film 50 to the scintillator 32 to be sufficientlyexhibited. Furthermore, this also enables the risk of an air layer beingformed between the scintillator 32 and the reflective film 50 to besuppressed. Were an air layer to be formed between the scintillator 32and the reflective film 50, then there would be concern that multiplereflection of the light emitted from the scintillator 32 might occur,with the light being repeatedly reflected between the air layer and thescintillator 32, and between the air layer and the reflective film 50.Moreover, making the thickness of the adhesion layer 51 not greater than7 μm enables a reduction in modulation transfer function (MTF) anddetective quantum efficiency (DQE) to be suppressed.

The reflective film 50 covers the entire front surface of the adhesionlayer 51. The reflective film 50 has a function of reflecting the lightconverted in the scintillator 32. The reflective film 50 is preferablyconfigured from an organic material. Examples of materials that may beemployed for the reflective film 50 include white polyethyleneterephthalate (PET), TiO₂, Al₂O₃, foamed white PET, polyester-based highreflectivity sheets, specular reflective aluminum, and the like. Notethat white PET is PET to which a white pigment, such as TiO₂, bariumsulfate, or the like, has been added. Moreover, polyester-based highreflectivity sheets are sheets (films) having a multi-layer structure ofplural superimposed thin polyester sheets. Foamed white PET is white PEThaving a porous surface. The thickness of the reflective film 50 ispreferably from 10 μm to 40 μm.

The bonding layer 52 covers the entire front surface of the reflectivefilm 50. The end portion of the bonding layer 52 also extends as far asthe front surface of the substrate 34. Namely, the bonding layer 52 isbonded to the substrate 34 at these end portions. The bonding layer 52has a function to fix the reflective film 50 and the protective layer 53to the scintillator 32. The same materials as may be employed in theadhesion layer 51 may be employed as the material of the bonding layer52. However, the bonding strength of the bonding layer 52 is preferablygreater than the bonding strength of the adhesion layer 51.

The protective layer 53 covers the entire front surface of the bondinglayer 52. Namely, the protective layer 53 is provided so as to cover theentirety of the scintillator 32, and an end portion of the protectivelayer 53 also covers a portion of the substrate 34. The protective layer53 functions as a moisture-proof film to prevent the ingress of moistureinto the scintillator 32. Examples of materials that may be employed asthe material of the protective layer 53 include organic films includingan organic material, such as PET, polyphenylene sulfide (PPS), orientedpolypropylene (OPP), polyethylene naphthalate (PEN), polyimide (PI), andthe like. Moreover, an ALPET (registered trademark) sheet in which analuminum layer such as an aluminum foil is bonded to an insulating sheet(film) such as polyethylene terephthalate may be employed as theprotective layer 53.

The bending suppression member 60 is provided on the front surface ofthe protective layer 53, with the bonding layer 54 interposedtherebetween. The same materials as may be employed in the adhesionlayer 51 and the bonding layer 52 may, for example, be employed as thematerial of the bonding layer 54.

In the example illustrated in FIG. 13, the bending suppression member 60extends over regions corresponding to the central portion 33A and theperipheral edge portion 33B of the scintillator 32, with an outerperipheral portion of the bending suppression member 60 angled so as tofollow the slope of the peripheral edge portion 33B of the scintillator32. The bending suppression member 60 is bonded to the protective layer53 through the bonding layer 54 at both the region corresponding to thecentral portion 33A of the scintillator 32 and the region correspondingto the peripheral edge portion 33B of the scintillator 32. In theexample illustrated in FIG. 13, an end portion of the bendingsuppression member 60 is disposed in a region corresponding to theperipheral edge portion 33B of the scintillator 32.

As illustrated in FIG. 14, the bending suppression member 60 may beprovided only in the region corresponding to the central portion 33A ofthe scintillator 32. In such cases, the bending suppression member 60 isbonded to the protective layer 53 through the bonding layer 54 in theregion corresponding to the central portion 33A of the scintillator 32.

As illustrated in FIG. 15, in cases in which the bending suppressionmember 60 extends over regions corresponding to both the central portion33A and the peripheral edge portion 33B of the scintillator 32, thebending suppression member 60 may be configured without providing anangled portion to follow the slope of the outer peripheral portions ofthe scintillator 32. In such cases, the bending suppression member 60 isbonded to the protective layer 53 through the bonding layer 54 in theregion corresponding to the central portion 33A of the scintillator 32.A space corresponding to the slope of the peripheral edge portion 33B ofthe scintillator 32 is formed between the scintillator 32 (theprotective layer 53) and the bending suppression member 60 in the regioncorresponding to the peripheral edge portion 33B of the scintillator 32.

In this example the cable 20 is connected to terminals 35 provided inthe connection region 80 at the outer peripheral portion of thesubstrate 34. The substrate 34 is connected to a control board (see FIG.45) through the cable 20. There is a concern that the cable 20 mightdetach from the substrate 34 or positional misalignment might arise werebending of the substrate 34 to occur. In such cases it would benecessary to perform a task to reconnect the cable 20 and the substrate34. This task to reconnect the cable 20 and the substrate 34 is calledre-work. As illustrated in FIG. 13 to FIG. 15, by arranging the endportion of the bending suppression member 60 at the inside of the endportion of the scintillator 32, re-work can be performed more easilythan in cases in which the bending suppression member 60 extends to thevicinity of the connection region 80.

As illustrated in FIG. 16 to FIG. 19, the end portion of the bendingsuppression member 60 may be disposed outside the end portion of thescintillator 32, and the end portions of the bonding layer 52 and theprotective layer 53 that both extend onto the substrate 34 may beprovided so as to be aligned with each other. Note that there is no needfor the position of the end portion of the bending suppression member 60to align exactly with the position of the end portions of the bondinglayer 52 and the protective layer 53.

In the example illustrated in FIG. 16, the bending suppression member 60is bonded to the protective layer 53 through the bonding layer 54 in theregion corresponding to the central portion 33A of the scintillator 32,and a space corresponding to the slope at the peripheral edge portion33B of the scintillator 32 is formed between the scintillator 32 (theprotective layer 53) and the bending suppression member 60 in the regioncorresponding to the peripheral edge portion 33B of the scintillator 32and also in a region further to the outside thereof.

In the example illustrated in FIG. 17, a filler 55 is provided in thespace formed between the scintillator 32 (the protective layer 53) andthe bending suppression member 60 at the region corresponding to theperipheral edge portion 33B of the scintillator 32 and also at theregion further to the outside thereof. The material of the filler 55 isnot particularly limited, and examples of materials that may be employedtherefor include, for example, resins. Note that in the exampleillustrated in FIG. 17 the bonding layer 54 is provided in the entireregion between the bending suppression member 60 and the filler 55 inorder to fix the bending suppression member 60 to the filler 55.

The method of forming the filler 55 is not particularly limited. Forexample, after forming the bonding layer 54 and the bending suppressionmember 60 in sequence on the scintillator 32 covered by the adhesionlayer 51, the reflective film 50, the bonding layer 52, and theprotective layer 53, a flowable filler 55 may be poured into be thespace formed between the scintillator 32 (the protective layer 53) andthe bending suppression member 60, and the filler 55 then cured.Moreover, for example, after forming the scintillator 32, the adhesionlayer 51, the reflective film 50, the bonding layer 52, and theprotective layer 53 in sequence on the substrate 34, the filler 55 maybe formed, and the bonding layer 54 and the bending suppression member60 may then be formed in sequence so as to cover the scintillator 32covered by the adhesion layer 51, the reflective film 50, the bondinglayer 52, and the protective layer 53 and also cover the filler 55.

By filling the filler 55 into the space formed between the scintillator32 (the protective layer 53) and the bending suppression member 60 inthis manner, the bending suppression member 60 and the scintillator 32(the protective layer 53) can be better suppressed from detaching fromone another than in the embodiment illustrated in FIG. 16. Furthermore,due to adopting a structure in which the scintillator 32 is fixed to thesubstrate 34 by both the bending suppression member 60 and the filler55, the scintillator 32 from the substrate 34 can be suppressed fromdetaching from one another.

In the example illustrated in FIG. 18, the outer peripheral portion ofthe bending suppression member 60 is angled so as to follow the slope ofthe peripheral edge portion 33B of the scintillator 32, and so as alsoto cover the portions of the bonding layer 52 and the protective layer53 that cover the substrate 34. Moreover, the end portion of the bendingsuppression member 60 and the end portions of the bonding layer 52 andthe protective layer 53 are aligned with each other. Note that there isno need for the position of the end portion of the bending suppressionmember 60 to align exactly with the position of the end portions of thebonding layer 52 and the protective layer 53.

The end portions of the bending suppression member 60, the bonding layer54, the protective layer 53, and the bonding layer 52 are sealed with asealing member 57. The sealing member 57 is preferably provided in aregion spanning from the front surface of the substrate 34 to the frontsurface of the bending suppression member 60, and in a region notcovering the pixel region 41A. Resins may be employed as the material ofthe sealing member 57, and thermoplastic resins are particularlypreferably employed therefor. Specifically glues such as acrylic glues,urethane based glues, and the like may be employed as the sealing member57. The bending suppression member 60 has a higher rigidity than that ofthe protective layer 53, and there is a concern that recovery force dueto the angle attempting to straighten out at the angled portion of thebending suppression member 60 might act to cause the protective layer 53to detach. Sealing the end portions of the bending suppression member60, the bonding layer 54, the protective layer 53, and the bonding layer52 using the sealing member 57 enables such detachment of the protectivelayer 53 to be suppressed.

Similarly to in the embodiment illustrated in FIG. 17, in the exampleillustrated in FIG. 19, the filler 55 is provided in a space formedbetween the scintillator 32 (the protective layer 53) and the bendingsuppression member 60 at the region corresponding to the peripheral edgeportion 33B of the scintillator 32 and also at the region further to theoutside thereof. Moreover, in the region corresponding to the endportion of the scintillator 32 an additional and separate bendingsuppression member 60A is stacked on the front surface of the bendingsuppression member 60 with a bonding layer 54A interposed therebetween.More specifically, the bending suppression member 60A is provided in aregion straddling the end portion (outer edge, edge) of the scintillator32. The bending suppression member 60A may be configured from the samematerials as the bending suppression member 60. As illustrated in FIG.9, the amount of bending of the substrate 34 is comparatively large atthe end portions of the scintillator 32. Forming a multi-layer structureusing the bending suppression members 60 and 60A at the regioncorresponding to the end portion of the scintillator 32 enables theeffect of suppressing bending of the substrate 34 at the end portion ofthe scintillator 32 to be enhanced.

As illustrated in FIG. 16 to FIG. 19, in cases in which the end portionof the bending suppression member 60 is arranged further to the outsidethan the end portion of the scintillator 32 and is provided so as to bealigned with the end portions of the bonding layer 52 and the protectivelayer 53, re-work can also be performed more easily than in cases inwhich the bending suppression member 60 extends as far as the vicinityof the connection region 80.

As illustrated in FIG. 20 to FIG. 23, a configuration may be adopted inwhich the end portion of the bending suppression member 60 is providedso as to be positioned further outside than the end portions of thebonding layer 52 and the protective layer 53 that extend onto thesubstrate 34, and so as to be positioned at the inside of the endportion of the substrate 34.

In the example illustrated in FIG. 20, the bending suppression member 60is bonded to the protective layer 53 through the bonding layer 54 at theregion corresponding to the central portion 33A of the scintillator 32,and in the region corresponding to the peripheral edge portion 33B ofthe scintillator 32 and also in the region further to the outsidethereof a space corresponding to the slope of the peripheral edgeportion 33B of the scintillator 32 is formed between the scintillator 32(the protective layer 53) and the bending suppression member 60, andbetween the substrate 34 and the bending suppression member 60.

In the example illustrated in FIG. 21, the end portion of the bendingsuppression member 60 is supported by a spacer 39. Namely, one end ofthe spacer 39 is connected to the first surface S1 of the substrate 34,and the other end of the spacer 39 is connected to the end portion ofthe bending suppression member 60 through a bonding layer 56. Bysupporting the end portion of the bending suppression member 60 thatextends so as to form a space between itself and the substrate 34 usingthe spacer 39, detachment of the bending suppression member 60 can besuppressed. Moreover, the bending suppression effect from the bendingsuppression member 60 can be caused to act as far as the vicinity of theend portion of the substrate 34. Note that instead of providing thespacer 39, a filler may be filled into the space formed between thescintillator 32 (the protective layer 53) and the bending suppressionmember 60, and between the substrate 34 and the bending suppressionmember 60, in a similar manner to the example illustrated in FIG. 17.

In the example illustrated in FIG. 22, the outer peripheral portion ofthe bending suppression member 60 is angled so as to follow the slope atthe peripheral edge portion 33B of the scintillator 32, and the outerperipheral portion of the bending suppression member 60 covers theportion where the bonding layer 52 and the protective layer 53 cover thesubstrate 34 and also covers the substrate 34 at the outside thereof.Namely, the end portions of the bonding layer 52 and the protectivelayer 53 are sealed by the bending suppression member 60. The portionsof the bending suppression member 60 that extend over the substrate 34are bonded to the substrate 34 though the bonding layer 54. By coveringthe end portions of the bonding layer 52 and the protective layer 53using the bending suppression member 60 in this manner, detachment ofthe protective layer 53 can be suppressed. Note that a sealing membermay be employed to seal the end portions of the bending suppressionmember 60, in a similar manner to the example illustrated in FIG. 18.

In the example illustrated in FIG. 23, in an embodiment in which the endportion of the bending suppression member 60 is supported by the spacer39, an additional and separate bending suppression member 60A is stackedon a front surface of the bending suppression member 60 at a regioncorresponding to the end portion of the scintillator 32, with a bondinglayer 54A interposed therebetween. More specifically, the bendingsuppression member 60A is provided in a region straddling the endportion (outer edge, edge) of the scintillator 32. The bendingsuppression member 60A may be configured from the same materials as thebending suppression member 60. As illustrated in FIG. 9, the amount ofbending of the substrate 34 is comparatively large at the end portionsof the scintillator 32. Forming a multi-layer structure using thebending suppression members 60 and 60A at the region corresponding tothe end portion of the scintillator 32 enables the effect of suppressingbending of the substrate 34 to be enhanced at the end portion of thescintillator 32. Note that instead of providing the spacer 39, a fillermay be filled into the space formed between the scintillator 32 (theprotective layer 53) and the bending suppression member 60, and betweenthe substrate 34 and the bending suppression member 60, in a similarmanner to the example illustrated in FIG. 17.

As illustrated in FIG. 24 to FIG. 28, the end portion of the bendingsuppression member 60 may be provided so as to be aligned with the endportion of the substrate 34. Note that there is no need for the positionof the end portion of the bending suppression member 60 to align exactlywith the position of the end portion of the substrate 34.

In the example illustrated in FIG. 24, the bending suppression member 60is bonded to the protective layer 53 through the bonding layer 54 at aregion corresponding to the central portion 33A of the scintillator 32,and a space corresponding to the slope of the peripheral edge portion33B of the scintillator 32 is formed between the scintillator 32 (theprotective layer 53) and the bending suppression member 60, and betweenthe substrate 34 and the bending suppression member 60, at a regioncorresponding to the peripheral edge portion 33B of the scintillator 32and also at a region further to the outside thereof.

In the example illustrated in FIG. 25, the end portion of the bendingsuppression member 60 is supported by the spacer 39. Namely, one end ofthe spacer 39 is connected to the cable 20 provided at the end portionof the substrate 34, and the other end of the spacer 39 is connected tothe end portion of the bending suppression member 60 through a bondinglayer 56. By using the spacer 39 to support the end portion of thebending suppression member 60 that extends so as to form a space betweenitself and the substrate 34, detachment of the bending suppressionmember 60 can be suppressed. Moreover, the bending suppression effectfrom the bending suppression member 60 can be caused to act as far asthe vicinity of the end portion of the substrate 34.

In the example illustrated in FIG. 26, the space formed between thescintillator 32 (the protective layer 53) and the bending suppressionmember 60, and between the substrate 34 and the bending suppressionmember 60, is filled by the filler 55. In the present exemplaryembodiment the connection portions between the cable 20 and theterminals 35 are covered by the filler 55. Thus by filling the spaceformed between the scintillator 32 (the protective layer 53) and thebending suppression member 60, and between the substrate 34 and thebending suppression member 60, with the filler 55, the bendingsuppression member 60 and the scintillator 32 (the protective layer 53)can be better suppressed from detaching from one another than in theembodiment illustrated in FIG. 24. Furthermore, due to the scintillator32 having a structure fixed to the substrate 34 by both the bendingsuppression member 60 and the filler 55, the scintillator 32 and thesubstrate 34 can be suppressed from detaching from one another.Moreover, since the connection portions between the cable 20 and theterminals 35 are covered by the filler 55, detachment of the cable 20can also be suppressed.

In the example illustrated in FIG. 27, the outer peripheral portion ofthe bending suppression member 60 is angled so as to follow the slope ofthe peripheral edge portion 33B of the scintillator 32. The outerperipheral portion of the bending suppression member 60 also covers aportion where the bonding layer 52 and the protective layer 53 cover thesubstrate 34, a portion of the substrate at the outside thereof, and theconnection portion between the cable 20 and the terminals 35. Theportions of the bending suppression member 60 extending over thesubstrate 34 and over the cable 20 are respectively bonded to thesubstrate 34 and the cable 20 through the bonding layer 54. Theconnection portions between the cable 20 and the terminals 35 arecovered by the bending suppression member 60, enabling detachment of thecable 20 to be suppressed. Moreover, since the other end of the cable 20is anticipated to be connected to a control board mounted withelectronic components, there is a concern regarding comparatively largebending of the substrate 34 occurring at the connection portions betweenthe cable 20 and the terminals 35. The connection portions between thecable 20 and the terminals 35 are covered by the bending suppressionmember 60, enabling bending of the substrate 34 at these portions to besuppressed.

In the example illustrated in FIG. 28, a space formed between thescintillator 32 (the protective layer 53) and the bending suppressionmember 60, and between the substrate 34 and the bending suppressionmember 60, is filled with the filler 55. Moreover, an additional andseparate bending suppression member 60A is stacked on a front surface ofthe bending suppression member 60 at a region corresponding to the endportion of the scintillator 32, with a bonding layer 54A interposedtherebetween. More specifically, the bending suppression member 60A isprovided in a region straddling the end portion (outer edge, edge) ofthe scintillator 32. The bending suppression member 60A may beconfigured from the same materials as the bending suppression member 60.As illustrated in FIG. 9, the amount of bending of the substrate 34 iscomparatively large at the end portions of the scintillator 32. Forminga multi-layer structure using the bending suppression members 60 and 60Aat the region corresponding to the end portion of the scintillator 32enables the effect of suppressing bending of the substrate 34 to beenhanced at the end portion of the scintillator 32.

As illustrated in FIG. 29 to FIG. 33, the end portion of the bendingsuppression member 60 may be provided so as to be in a position furtheroutside than the end portion of the substrate 34.

In the example illustrated in FIG. 29, the bending suppression member 60is bonded to the protective layer 53 through the bonding layer 54 at aregion corresponding to the central portion 33A of the scintillator 32,and a space corresponding to the slope of the peripheral edge portion33B of the scintillator 32 is formed between the scintillator 32 (theprotective layer 53) and the bending suppression member 60, and betweenthe substrate 34 and the bending suppression member 60, at the regioncorresponding to the peripheral edge portion 33B of the scintillator 32and also at the region further to the outside thereof.

In the example illustrated in FIG. 30, the end portion of the bendingsuppression member 60 is supported by the spacer 39. Namely, one end ofthe spacer 39 is connected to the cable 20 provided at the end portionof the substrate 34, and the other end of the spacer 39 is connected tothe end portion of the bending suppression member 60 through a bondinglayer 56. By using the spacer 39 to support the end portion of thebending suppression member 60 that extends so as to form the spacebetween itself and the substrate 34, detachment of the bendingsuppression member 60 can be suppressed. Moreover, the bendingsuppression effect from the bending suppression member 60 can be causedto act as far as the vicinity of the end portion of the substrate 34.

In the example illustrated in FIG. 31, the filler 55 is filled into thespace formed between the scintillator 32 (the protective layer 53) andthe bending suppression member 60, and between the substrate 34 and thebending suppression member 60. In the present exemplary embodiment theconnection portions between the cable 20 and the terminals 35 arecovered by the filler 55. By filling the filler 55 into the space formedbetween the scintillator 32 (the protective layer 53) and the bendingsuppression member 60 and between the substrate 34 and the bendingsuppression member 60 in this manner, the bending suppression member 60and the scintillator 32 (the protective layer 53) can be bettersuppressed from detaching from one another than in the embodimentillustrated in FIG. 29. Furthermore, due to the scintillator 32 having astructure fixed to the substrate 34 by both the bending suppressionmember 60 and the filler 55, the scintillator 32 and the substrate 34can be suppressed from detaching from one another. Moreover, since theconnection portions between the cable 20 and the terminals 35 arecovered by the filler 55, detachment of the cable 20 can be suppressed.

In the example illustrated in FIG. 32, the outer peripheral portion ofthe bending suppression member 60 is angled so as to follow the slope ofthe peripheral edge portion 33B of the scintillator 32. The outerperipheral portion of the bending suppression member 60 also covers theportion where the bonding layer 52 and the protective layer 53 cover thesubstrate 34, the portion on the substrate at the outside thereof, andthe connection portion between the cable 20 and the terminals 35. Theportions of the bending suppression member 60 extending over thesubstrate 34 and over the cable 20 are respectively bonded to thesubstrate 34 and the cable 20 through the bonding layer 54. By coveringthe connection portions between the cable 20 and the terminals 35 withthe bending suppression member 60, detachment of the cable 20 can besuppressed. Moreover, since the other end of the cable 20 is anticipatedto be connected to a control board mounted with electronic components,there is a concern regarding comparatively large bending of thesubstrate 34 at the connection portions between the cable 20 and theterminals 35. The connection portions between the cable 20 and theterminals 35 are covered by the bending suppression member 60, enablingbending of the substrate 34 at these portions to be suppressed.

In the example illustrated in FIG. 33, the filler 55 is filled into thespace formed between the scintillator 32 (the protective layer 53) andthe bending suppression member 60 and between the substrate 34 and thebending suppression member 60. Moreover, an additional and separatebending suppression member 60A is stacked on a front surface of thebending suppression member 60 at a region corresponding to the endportion of the scintillator 32, with a bonding layer MA interposedtherebetween. More specifically, the bending suppression member 60A isprovided in a region straddling the end portion (outer edge, edge) ofthe scintillator 32. The bending suppression member 60A may beconfigured from the same materials as the bending suppression member 60.As illustrated in FIG. 9, the amount of bending of the substrate 34 iscomparatively large at the end portions of the scintillator 32. Forminga multi-layer structure using the bending suppression members 60 and 60Aat the region corresponding to the end portion of the scintillator 32enables the effect of suppressing bending of the substrate 34 to beenhanced at the end portion of the scintillator 32.

In processes to manufacture the radiation detector 30, the flexiblesubstrate 34 is stuck to a support body, such as a glass substrate orthe like, and then after stacking the scintillator 32 onto the substrate34, the support body is detached from the substrate 34. When this isperformed bending occurs in the flexible substrate 34, and there is aconcern that the pixels 41 formed on the substrate 34 might be damagedthereby. By stacking the bending suppression member 60 on thescintillator 32 as in the embodiments illustrated in the examples ofFIG. 13 to FIG. 33 prior to detaching the support body from thesubstrate 34, the bending of the substrate 34 that occurs when thesupport body is being detached from the substrate 34 can be suppressed,enabling the risk of damage of the pixels 41 to be reduced.

FIG. 34 to FIG. 39 are cross-sections illustrating examples ofinstallation embodiments of bending suppression members in cases inwhich bending suppression members are provided on the second surface S2side of the substrate 34, this being the opposite side to the firstsurface S1 that contacts the scintillator 32.

In each of the examples of FIG. 34 to FIG. 39, substantially the entiresecond surface S2 of the substrate 34 is in contact with the bendingsuppression member 60 through the bonding layer 54. Namely, the surfacearea of the bending suppression member 60 is substantially the same asthe surface area of the substrate 34. An additional and separate bendingsuppression member 60A is stacked on the face of the bending suppressionmember 60 that is on the opposite side to the face on the substrate 34side of the bending suppression member 60, with a bonding layer 54Ainterposed therebetween. The bending suppression member 60A may beconfigured from the same materials as the bending suppression member 60.In cases in which an irradiation side sampling (ISS) approach is adoptedas the imaging method of the radiation detector 30, the bendingsuppression member 60A is preferably provided only on the outerperipheral portion of the substrate 34 in order to keep the surface areaof the overlapping portion between the bending suppression member 60Aand the pixel region 41A as small as possible. Namely, the bendingsuppression member 60A may have a ring shape including an opening 61 ata portion corresponding to the pixel region 41A, as illustrated in FIG.34 to FIG. 39. Thus forming a multi-layer structure using the bendingsuppression members 60 and 60A at the outer peripheral portion of thesubstrate 34 enables the rigidity of the outer peripheral portion of thesubstrate 34 that is comparatively susceptible to bending to bereinforced.

In the examples illustrated in FIG. 34 to FIG. 36, the bendingsuppression member 60A is provided in a region straddling the endportion (outer edge, edge) of the scintillator 32. As illustrated inFIG. 9, the amount of bending of the substrate 34 is comparatively largeat the end portions of the scintillator 32. Forming a multi-layerstructure using the bending suppression members 60 and 60A at the regioncorresponding to the end portion of the scintillator 32 enables theeffect of suppressing bending of the substrate 34 to be enhanced at theend portion of the scintillator 32.

In cases in which an irradiation side sampling (ISS) approach is adoptedas the imaging method of the radiation detector 30, there is a concernthat were a portion of the bending suppression member 60A to overlapwith the pixel region 41A as illustrated in FIG. 34, depending on thesubstance employed in the bending suppression member 60A this might havean impact on the images. In cases in which a portion of the bendingsuppression member 60A overlaps with the pixel region 41A, a plastic istherefore preferably employed for the material of the bendingsuppression member 60A.

Most preferably an embodiment is adopted in which, as illustrated inFIG. 35 and FIG. 36, the bending suppression member 60A straddles theend portion (outer edge, edge) of the scintillator 32 but does notoverlap with the pixel region 41A (namely, an embodiment in which anedge of the opening 61 of the bending suppression member 60A is disposedat the outside of the pixel region 41A). In the example illustrated inFIG. 35, the position of the edge of the opening 61 of the bendingsuppression member 60A is substantially aligned with the position of theend portion of the pixel region 41A. In the example illustrated in FIG.36, the edge of the opening 61 of the bending suppression member 60A isdisposed between the end portion of the pixel region 41A and the endportion of the scintillator 32.

Moreover, the position of the edge of the opening 61 of the bendingsuppression member 60A may be disposed so as to be substantially alignedwith the position of the end portion of the scintillator 32 asillustrated in FIG. 37, or may be disposed so as to be further outsidethan the end portion of the scintillator 32 as illustrated in FIG. 38.In such cases there is no structure present where the bendingsuppression member 60A straddles the end portion (outer edge, edge) ofthe scintillator 32, and so there might be a concern regarding alessening of the effect of suppressing bending of the substrate 34 atthe end portion of the scintillator 32. However, due to forming amulti-layer structure using the bending suppression members 60 and 60Aat the outer peripheral portion of the substrate 34 where the connectionportions between the cable 20 and the terminals 35 are present, theeffect of suppressing bending of the substrate 34 at the connectionportions between the cable 20 and the terminals 35 is maintained.

In the example illustrated in FIG. 39, the surface area of the bendingsuppression member 60 is larger than the surface area of the substrate34, and the end portion of the bending suppression member 60 is disposedfurther outside than the end portion of the substrate 34. Adopting suchan embodiment enables the radiation detector 30 to be fixed to theinside of the case 14 by screwing a portion of the bending suppressionmember 60 that juts out from the substrate 34 to the case 14, or thelike.

Note that although examples are illustrated in FIG. 34 to FIG. 39 ofembodiments in which the position of the outside end portion of thebending suppression member 60A is substantially aligned with theposition of the end portion of the substrate 34, there is no limitationto such embodiments. The outside end portion of the bending suppressionmember 60A may be disposed further to the outside or inside than the endportion of the substrate 34.

Although examples are illustrated in FIG. 34 to FIG. 39 of embodimentsin which a multi-layer structure is formed using the bending suppressionmembers 60 and 60A at the second surface S2 side of the substrate 34,there is no limitation to such embodiments. For example, in cases inwhich the bending suppression member 60 is provided at the scintillator32 side as in the examples of embodiments illustrated in FIG. 13 to FIG.33, the bending suppression member 60A may be provided alone at thesecond surface S2 side of the substrate 34 in order to reinforce theouter peripheral portion of the substrate 34.

FIG. 40 is a plan view illustrating an example of a structure of thebending suppression member 60. A main face of the bending suppressionmember 60 may include plural through holes 62. The size and pitch of thethrough holes 62 is prescribed so as to obtain the desired rigidity ofthe bending suppression member 60.

Including the plural through holes 62 in the bending suppression member60 enables air introduced at the joining face of the bending suppressionmember 60 to the scintillator 32 side or the substrate 34 side to escapethrough the through holes 62. This enables air bubbles to be suppressedfrom being generated at the joining face of the bending suppressionmember 60 to the scintillator 32 side or the substrate 34 side.

There is a concern that air bubbles might be generated at the joiningface if no mechanism is provided to allow air introduced at the joiningface of the bending suppression member 60 to the scintillator 32 side orthe substrate 34 side to escape. For example, were air bubbles arisingat the joining face to expand due to heat during operation of theradiographic imaging device 10, there would be a drop in the cohesionbetween the bending suppression member 60 and the scintillator 32 sideor the substrate 34 side. This would lead to a concern that the bendingsuppression effect from the bending suppression member 60 might not besufficiently exhibited. By using the bending suppression member 60including the plural through holes 62 as illustrated in FIG. 40, thegeneration of air bubbles at the joining face of the bending suppressionmember 60 to the scintillator 32 side or the substrate 34 side can besuppressed as described above, enabling the cohesion between the bendingsuppression member 60 and the scintillator 32 side or the substrate 34side to be maintained. This enables the bending suppression effect ofthe bending suppression member 60 to be maintained.

FIG. 41 is a perspective view illustrating another example of thestructure of the bending suppression member 60. In the exampleillustrated in FIG. 41, the bending suppression member 60 includes anindented and protruding structure on the joining face to thescintillator 32 side or the substrate 34 side. The indented andprotruding structure may be configured including plural grooves 63arranged parallel to each other, as illustrated in FIG. 41. The face ofthe bending suppression member 60 that includes the indented andprotruding structure configured from the plural grooves 63 is, forexample as illustrated in FIG. 42, joined to the scintillator 32 thathas been covered by the reflective film 50. In this manner, due to thebending suppression member 60 including the indented and protrudingstructure on the joining face to the scintillator 32 side or thesubstrate 34 side, any air introduced to the joining portion of thebending suppression member 60 and the scintillator 32 side or thesubstrate 34 side is able to escape through the grooves 63. Similarly toin the embodiment illustrated in FIG. 40, this accordingly enables thegeneration of air bubbles at the joining face of the bending suppressionmember 60 to the scintillator 32 side or the substrate 34 side to besuppressed. This enables the cohesion between the bending suppressionmember 60 and the scintillator 32 side or the substrate 34 side to bemaintained, and enables the bending suppression effect of the bendingsuppression member 60 to be maintained.

FIG. 43 and FIG. 44 are plan views illustrating other example ofstructures of the bending suppression member 60. As illustrated in FIG.43 and FIG. 44, the bending suppression member 60 may be segmented intoplural pieces 64. The bending suppression member 60 may, as illustratedin FIG. 43, be segmented into the plural pieces 64 arrayed along onedirection. Moreover, the bending suppression member 60 may, asillustrated in FIG. 44, be segmented into the plural pieces 64 arrayedin both a longitudinal direction and a lateral direction.

The greater the surface area of the bending suppression member 60, themore readily air bubbles are generated at the joining face of thebending suppression member 60 to the scintillator 32 side or thesubstrate 34 side. As illustrated in FIG. 43 and FIG. 44, segmenting thebending suppression member 60 into the plural pieces 64 enables airbubbles to be suppressed from being generated at the joining face of thebending suppression member 60 to the scintillator 32 side or thesubstrate 34 side. This enables the cohesion between the bendingsuppression member 60 and the scintillator 32 side or the substrate 34side to be maintained, and thereby enables the bending suppressioneffect of the bending suppression member 60 to be maintained.

FIG. 45 to FIG. 47 are diagrams respectively illustrating otherconfiguration examples of the radiographic imaging device 10. Theradiographic imaging device 10 is configured including the case 14, theradiation detector 30 housed inside the case 14, and a control board 81and a power source 82.

The control board 81 is a board mounted with some or all of theelectronic components configuring the controller 29, the image memory28, the gate line driver 22, the charging amplifiers 24, and the signalprocessor 26 illustrated in FIG. 3. The control board 81 may be a rigidboard having a higher rigidity than that of the flexible substrate 34.The power source 82 supplies power through power lines 83 to theelectronic components mounted on the control board 81.

The case 14 is preferably lightweight, has a low absorption ratio toX-rays, and has high rigidity, and is preferably configured from amaterial that has an elastic modulus sufficiently higher than that ofthe bending suppression member 60. A material having a bending elasticmodulus of at least 10000 MPa is preferably employed as the material ofthe case 14. Examples of materials suitably employed as the material ofthe case 14 include carbon or carbon fiber reinforced plastics (CFRP)having a bending elastic modulus of around 20,000 MPa to 60,000 MPa.

When radiographic images are imaged using the radiographic imagingdevice 10, load is applied to the radiation-incident face 15 of the case14 by the imaging subject. In cases in which the bending suppressionmember 60 is, for example, configured from a material having acomparatively low elastic modulus, such as a soft plastic or the like,then there is a concern that were the rigidity of the case 14 to beinsufficient, then bending might occur in the substrate 34 under theload from the imaging subject, resulting in problems such as damage tothe pixels 41. By housing the radiation detector 30 equipped with thebending suppression member 60 inside the case 14 made from a materialhaving a bending elastic modulus of not less than 10,000 MPa, bending ofthe substrate 34 under load from the imaging subject can be suppressed,even in cases in which the bending suppression member 60 is configuredfrom a material having a comparatively low elastic modulus, such as asoft plastic or the like. By causing the bending suppression member 60and an inner wall face of the case 14 to cohere, the effect ofsuppressing bending of the substrate 34 under the load from the imagingsubject can be further enhanced. In such cases, the bending suppressionmember 60 and the inner wall face of the case 14 may be bonded through abonding layer, or may simply be placed in contact with each otherwithout interposing a bonding layer.

The examples illustrated in FIG. 45 and FIG. 46 are examples ofconfigurations in which the radiation detector 30, the control board 81,and the power source 82 are arranged next to each other along a lateraldirection in the drawings. As illustrated in FIG. 46, in the internalspace of the case 14, the thickness of a region housing the radiationdetector 30 may be made thinner than the thickness of a region housingthe control board 81 and the power source 82. Adopting this approachenables configuration of an ultra-thin portable electronic cassettehaving a thickness appropriate to the thickness of the radiationdetector 30. In order to soften a step formed between the region housingthe radiation detector 30 and the region housing the control board 81and the power source 82, the case 14 preferably includes a slopingportion 14A at a portion where these two regions are connected together.By including the sloping portion 14A in the case 14, any discomfort feltby a patient serving as the imaging subject can be reduced when theradiographic imaging device 10 is employed in a state inserted below thepatient.

In the example illustrated in FIG. 47, a base 37 having substantiallythe same size as that of the substrate 34 of the radiation detector 30is provided at a position overlapping with the substrate 34 within theinternal space of the case 14, and the control board 81 and the powersource 82 are provided on the base 37. Adopting such a configurationenables the size of the radiographic imaging device 10 in plan view tobe decreased in comparison to cases in which the radiation detector 30,the control board 81, and the power source 82 are arranged next to eachother along the lateral direction in the drawings. [0165] Allpublications, patent applications and technical standards mentioned inthe present specification are incorporated by reference in the presentspecification to the same extent as if each individual publication,patent application, or technical standard was specifically andindividually indicated to be incorporated by reference.

In a radiation detector according to a second aspect of technologydisclosed herein, the scintillator is stacked on a first surface side ofthe substrate, and the bending suppression member is stacked on at leastone side of a second surface side of the substrate that is on theopposite side to the first surface side, or a side corresponding to asurface of the scintillator on the opposite side to a surface of thescintillator contacting the substrate.

In a radiation detector according to a third aspect of technologydisclosed herein, the bending suppression member is stacked on both thesecond surface side of the substrate and the side corresponding to thesurface of the scintillator on the opposite side to the surface of thescintillator contacting the substrate.

In a radiation detector according to a fourth aspect of technologydisclosed herein, the bending suppression member has a higher rigiditythan the substrate.

In a radiation detector according to a fifth aspect of technologydisclosed herein, the bending suppression member extends so as to span awider range than an extension range of the scintillator.

In a radiation detector according to a sixth aspect of technologydisclosed herein, the substrate includes a connection region for aflexible wiring connection, and the bending suppression member isprovided in a region covering at least a portion of the connectionregion and also covering the scintillator.

In a radiation detector according to a seventh aspect of technologydisclosed herein, the bending suppression member has a bending elasticmodulus of from 1000 MPa to 3500 MPa.

In a radiation detector of according to an eighth aspect of technologydisclosed herein, a ratio of a coefficient of thermal expansion of thebending suppression member against a coefficient of thermal expansion ofthe scintillator is from 0.5 to 2.

In a radiation detector according to a ninth aspect of technologydisclosed herein, a coefficient of thermal expansion of the bendingsuppression member is from 30 ppm/K to 80 ppm/K.

In a radiation detector according to a tenth aspect of technologydisclosed herein, the bending suppression member is configured includingat least one out of acrylic, polycarbonate, or polyethyleneterephthalate.

A radiation detector according to an eleventh aspect of technologydisclosed herein further includes a reinforcement member that isprovided in a region straddling an end portion of the scintillator so asto reinforce a bending suppression effect of the bending suppressionmember.

In a radiation detector according to a twelfth aspect of technologydisclosed herein, the reinforcement member has a higher rigidity thanthe substrate.

In a radiation detector according to a thirteenth aspect of technologydisclosed herein, the reinforcement member is configured from a materialthat is the same as a material of the bending suppression member.

In a radiation detector according to a fourteenth aspect of technologydisclosed herein, the substrate is configured including a resin film.

In a radiation detector according to a fifteenth aspect of technologydisclosed herein, the substrate is configured including a base membermade from a resin material including a fine particle layer containingfine particles of an inorganic material having a mean particle size offrom 0.05 μm to 2.5 μm. The fine particle layer is provided on a secondsurface side of the substrate that is on the opposite side to a firstsurface of the substrate provided with the plural pixels.

In a radiation detector according to a sixteenth aspect of technologydisclosed herein, the fine particles include an element having an atomicnumber that is greater than an atomic number of elements configuring theresin material and that is an atomic number not exceeding 30.

In a radiation detector according to a seventeenth aspect of technologydisclosed herein, the substrate has a coefficient of thermal expansionnot greater than 20 ppm/K in a temperature range from 300° C. to 400° C.

In a radiation detector according to an eighteenth aspect of technologydisclosed herein, the substrate satisfies at least one condition out ofhaving a heat shrinkage ratio in a machine direction at 400° C. and at asubstrate thickness of 25 μm of not greater than 0.5%, or having amodulus of elasticity at 500° C. of not less than 1 GPa.

A radiation detector according to a nineteenth aspect of technologydisclosed herein further includes a buffer layer that is providedbetween the substrate and the scintillator and that has a coefficient ofthermal expansion lying between the coefficient of thermal expansion ofthe substrate and the coefficient of thermal expansion of thescintillator.

A radiographic imaging device according to a twentieth aspect oftechnology disclosed herein includes the radiation detector of any oneof the first to nineteenth aspects, a reading section configured toperform reading of electrical charge accumulated in the pixels, and ageneration section configured to generate image data based on theelectrical charge read from the pixels.

A radiographic imaging device according to a twenty-first aspect oftechnology disclosed herein further includes a case that houses theradiation detector and that includes a radiation-incident face to whichradiation is incident, and out of the substrate and the scintillator,the substrate is disposed on a side corresponding to theradiation-incident face.

A radiation detector manufacturing method according to a twenty-secondaspect of technology disclosed herein includes a process of formingplural pixels on a flexible substrate such that each pixel includes aphotoelectric conversion element, a process of forming a scintillator onthe substrate, and a process of arranging a bending suppression memberconfigured to suppress bending of the substrate. The bending suppressionmember is set with higher rigidity the greater a pixel size.

In a manufacturing method according to a twenty-third aspect oftechnology disclosed herein, the bending suppression member has arigidity satisfying R≥X²/2Z_(L), wherein X is the pixel size, Z_(L) is acritical deformation amount of the pixel through bending of thesubstrate, and R is a radius of curvature of bending occurring in thesubstrate due to the weight of the scintillator.

Advantageous Effects of Invention

The first aspect of technology disclosed herein enables the risk ofdamage to pixels caused by bending occurring in the substrate due to theweight of the scintillator to be reduced in comparison to cases lackinga bending suppression member having a rigidity prescribed according tothe pixel size.

The second aspect of technology disclosed herein enables a bendingsuppression effect to be effectively exhibited by the bendingsuppression member.

The third aspect of technology disclosed herein enables the risk ofdamage to pixels caused by bending of the substrate to be furtherreduced.

The fourth aspect of technology disclosed herein enables a bendingsuppression effect to be effectively exhibited by the bendingsuppression member.

The fifth aspect of technology disclosed herein enables a bendingsuppression effect to be effectively exhibited by the bendingsuppression member.

The sixth aspect of technology disclosed herein enables a bendingsuppression effect to be effectively exhibited by the bendingsuppression member.

The seventh aspect of technology disclosed herein enables a preferablerigidity to be achieved for the bending suppression member.

The eighth aspect of technology disclosed herein enables the risk of thesubstrate and the scintillator detaching from one another to besuppressed in comparison to cases in which the ratio of the coefficientof thermal expansion of the bending suppression member against thecoefficient of thermal expansion of the scintillator does not lie in thestated range.

The ninth aspect of technology disclosed herein enables the risk of thesubstrate and the scintillator detaching from one another to besuppressed in comparison to cases in which the coefficient of thermalexpansion of the bending suppression member does not lie in the statedrange.

The tenth aspect of technology disclosed herein enables a bendingsuppression effect to be more effectively exhibited by the bendingsuppression member, and the risk of the substrate and the scintillatordetaching from one another to be suppressed, in comparison to cases inwhich a configuration is adopted in which the bending suppression memberis configured including another material.

The eleventh aspect of the technology disclosed herein enables bendingof a portion of the substrate corresponding to the end portion of thescintillator to be suppressed in comparison to cases in which noreinforcement member is provided.

In the twelfth aspect of technology disclosed herein, an effect ofreinforcing the bending suppression effect of the bending suppressionmember is effectively exhibited.

In the thirteenth aspect of technology disclosed herein, an effect ofreinforcing the bending suppression effect of the bending suppressionmember is effectively exhibited.

The fourteenth aspect of technology disclosed herein enables a morelightweight and lower cost radiation detector to be achieved comparedwith cases in which a glass substrate is employed as the material forthe substrate, and moreover enables the risk of impact damage to thesubstrate to be reduced.

The fifteenth aspect of technology disclosed herein enables backscattering radiation to be suppressed from being generated in thesubstrate in comparison to cases in which the substrate does not includea fine particle layer.

The sixteenth aspect of technology disclosed herein enables effectivesuppression of back scattering radiation while also enabling absorptionof radiation in the fine particle layer to be suppressed in comparisonto cases in which the atomic number of the fine particles is not withinthe stated range.

The seventeenth aspect of technology disclosed herein enables moreappropriate pixel formation on the substrate than in cases in which thecoefficient of thermal expansion of the substrate is not within thestated range.

The eighteenth aspect of technology disclosed herein enables moreappropriate pixel formation on the substrate than in cases in which theheat shrinkage ratio and modulus of elasticity of the substrate are notwithin the stated ranges.

The nineteenth aspect of technology disclosed herein enables thermalstress to be suppressed from acting at the interface between thesubstrate and the scintillator in comparison to cases in which a bufferlayer is not included.

The twentieth aspect of technology disclosed herein enables the risk ofdamage to the pixels caused by bending occurring in the substrate due tothe weight of the scintillator to be reduced in comparison to cases inwhich a bending suppression member having a rigidity prescribedaccording to the pixel size is not employed.

The twenty-first aspect of technology disclosed herein enables a higherresolution of radiographic images to be achieved than in cases in which,from out of the substrate and the scintillator, the scintillator isdisposed on the side of the radiation-incident face.

The twenty-second aspect of technology disclosed herein enables the riskof damage to the pixels caused by bending occurring in the substrate dueto the weight of the scintillator to be reduced in comparison to casesin which a bending suppression member having a rigidity prescribedaccording to the pixel size is not employed.

The twenty-third aspect of technology disclosed herein enables areduction in the risk of damage to the pixels caused by bendingoccurring in the substrate due to the weight of the scintillator to besecured.

What is claimed is:
 1. A radiation detector comprising: a flexiblesubstrate; a plurality of pixels provided on the substrate and eachincluding a photoelectric conversion element; a scintillator stacked onthe substrate; and a bending suppression member configured to suppressbending of the substrate; the bending suppression member having arigidity that satisfiesR≥X ²/2Z _(L) wherein X is a pixel size, Z_(L) is a critical deformationamount of the pixel through bending of the substrate, and R is a radiusof curvature of bending occurring in the substrate due to the weight ofthe scintillator.
 2. The radiation detector of claim 1, wherein: thescintillator is stacked on a first surface side of the substrate; andthe bending suppression member is stacked on at least one side of asecond surface side of the substrate that is on the opposite side to thefirst surface side, or a side corresponding to a surface of thescintillator on the opposite side to a surface of the scintillatorcontacting the substrate.
 3. The radiation detector of claim 2, whereinthe bending suppression member is stacked on both the second surfaceside of the substrate and the side corresponding to the surface of thescintillator on the opposite side to the surface of the scintillatorcontacting the substrate.
 4. The radiation detector of claim 1, whereinthe bending suppression member has a higher rigidity than the substrate.5. The radiation detector of claim 1, wherein the bending suppressionmember extends so as to span a wider range than an extension range ofthe scintillator.
 6. The radiation detector of claim 1, wherein: thesubstrate includes a connection region for a flexible wiring connection;and the bending suppression member is provided in a region covering atleast a portion of the connection region and also covering thescintillator.
 7. The radiation detector of claim 1, wherein the bendingsuppression member has a bending elastic modulus of from 1000 MPa to3500 MPa.
 8. The radiation detector of claim 1, wherein a ratio of acoefficient of thermal expansion of the bending suppression memberagainst a coefficient of thermal expansion of the scintillator is from0.5 to
 2. 9. The radiation detector of claim 1, wherein a coefficient ofthermal expansion of the bending suppression member is from 30 ppm/K to80 ppm/K.
 10. The radiation detector of claim 1, wherein the bendingsuppression member is configured including at least one out of acrylic,polycarbonate, or polyethylene terephthalate.
 11. The radiation detectorof claim 1, further comprising a reinforcement member that is providedin a region straddling an end portion of the scintillator so as toreinforce a bending suppression effect of the bending suppressionmember.
 12. The radiation detector of claim 11, wherein thereinforcement member has a higher rigidity than the substrate.
 13. Theradiation detector of claim 1, wherein the substrate is configuredincluding a resin film.
 14. The radiation detector of claim 1, whereinthe substrate has a coefficient of thermal expansion not greater than 20ppm/K in a temperature range from 300° C. to 400° C.
 15. The radiationdetector of claim 1, wherein the substrate satisfies at least onecondition out of: having a heat shrinkage ratio in a machine directionat 400° C. and at a substrate thickness of 25 μm of not greater than0.5%; or having a modulus of elasticity at 500° C. of not less than 1GPa.
 16. The radiation detector of claim 1, further comprising a bufferlayer that is provided between the substrate and the scintillator andthat has a coefficient of thermal expansion lying between thecoefficient of thermal expansion of the substrate and the coefficient ofthermal expansion of the scintillator.
 17. A radiographic imaging devicecomprising: the radiation detector of claim 1; a reading circuitconfigured to perform reading of electrical charge accumulated in thepixels; and a signal processor configured to generate image data basedon the electrical charge read from the pixels.
 18. The radiographicimaging device of claim 17, further comprising: a case that houses theradiation detector and that includes a radiation-incident face to whichradiation is incident; and out of the substrate and the scintillator,the substrate is disposed on a side corresponding to theradiation-incident face.
 19. A manufacturing method for a radiationdetector comprising: forming a plurality of pixels on a flexiblesubstrate such that each pixel includes a photoelectric conversionelement; forming a scintillator on the substrate; and arranging abending suppression member configured to suppress bending of thesubstrate; the bending suppression member being set with higher rigiditythe greater a pixel size.
 20. The manufacturing method of claim 19,wherein the bending suppression member has a rigidity satisfyingR≥X ²/2Z _(L) wherein X is the pixel size, Z_(L) is a criticaldeformation amount of the pixel through bending of the substrate, and Ris a radius of curvature of bending occurring in the substrate due tothe weight of the scintillator.